Wood I-Joist (IJ)
Wood I-Joist (IJ) is a kind of high-efficiency and load-bearing wood building material, which takes industrial fast-growing trees as raw materials. It can replace high-quality solid wood beams for modern light-weight wooden structures. Although the production and application of IJ for wooden structure shelf has been prevalent in developed countries, it is still blank in China. IJ’s main building application performance – end bearing capacity, end support length, lateral buckling performance of the whole beam, IJ shelf stiffness not only directly affects the bearing capacity, stability and residential feeling of light wood structure buildings, but also directly affects the expected quality and production control of IJ. On the one hand, the end of IJ resting on the roof beam directly bears the pressure from the weight of all the building components on it and the pressure from the end of the IJ resting on the metal connector (the end of IJ resting on the metal connector only bears the pressure from the latter), on the other hand, it bears the bending shear force from the end of IJ resting on the uniform load of people and objects. Therefore, it is necessary to focus on investigating the end of IJ including the end of IJ. Vertical compressive strength and bending shear strength of web and flange are studied. Without considering the stability of vertical compression plate, the vertical compressive strength of IJ with poplar veneer laminated lumber (LVL) as flange (8,700 Mpa in parallel grain tensile strength) and bamboo particleboard as web (22 Mpa in horizontal shear strength) is 5.70 Mpa, and the failure load of IJ with uniform load and bending shear force is 7.14 kN. The minimum supporting length of IJ on metal joints is 56.80 mm, which is required. The shear strength of LVL parallel layer is greater than 4.30 Mpa.